Double-back jack



July 9, 1929.

J. A. ADELL 1,719,955

DOUBLE RACK JACK Filed June 50, 1927 iff/enfer uw HHM Hlforngys y July 9, 1929. J A,. ADE`| 1,719,955

DOUBLE. RACK JACK Filed June 30. 1927 2 Sheets-Sheet 2 35' 27 In 'Il 26 m.; zo @s 57 l l; 6: 23 g2 j V Z4 Z 10 I3 2f 33 5;? 3a ya lmummm'mm [bre/7 for @y 9 dpi/2.14, 14M

Patented July 9, 1929. If i UNITED STATES PATENT FFICE.

JOI-IN A. ADELL, OF ORANGE; MASSACHUSETTS.

Application sied Julie 3o,

This invention relates to a ack comprising three telescoping parts which are so related that the jack can be lowered to a height about equal to the height ot' each one of said. parts, or to the tallest one, and can be raised automatically to a height nearly equal to the combined height ot the three parts, thus increasing the range of a rack jack.

The principal objects of the invention are to provide a' construction of this type in which the parts are all raised vertically throughout their whole range of motion; and in which the intern'iediate part steadies and stabilizes the inner raclr, which is the one moving to the greatest height and having the work-rest; to provide the intermediate part in the form of a vertically movable lifting member or guide, itself guided in the stationary traine or casing of the jack; to pro vide automatic means by which this intermediate member is automatically converted into a part of the rack when the inner rack reaches the limit of its elevation and thereafter moves upwardly by the use of the same pawls or other lifting device and without any change in the manipulation on the part of the operator; to provide this means with a movable rack member set into the back of the outer lifting member and adapted to be held out ot range oit the lifting apparatus or pawls at all times except when the inner rack is elevated to its limiting position with respect thereto7 to provide a construction in which these two telescoping racks constitute the complete rack for the jack and will be continuous and in alignment while the lower one is operating; to provide means by which the inner rack cannot descend while the lower rack section is in engagement with the pawls.7 but as soon as that is withdrawn, the inner rack will come automatically into operative co-operation with the pawls; so that it will not drop and especially to provide improvements in the details of the automatic mechanism above reterred to.

@their objects and advantages ot the invention will appear hereinafter.

Reference is to be had to the accompanying drawings; in which Fig. l is a side view of a jack constructed in accordance with this invention;

Fig. 2 is a front edge view ot the same with the operating handle shown in section;

Fig. 3 is a central sectional view on the DOUBLE-RACK JACK.

1927. Serial No. 202,672.

line 3-3 ot Fig. 2, showing the parts in the same position with the pawls operating on the upper rack only; i

Fig. 4L is a similar View, with parts omitted, showing the movement of the lower rack section into operative position below the upper rack;

Fig. 5 is a View similar to Fig. 3, showing the .load raised by the aid of the two rack sections;

Fig. 6 is a horizontal sectional view on the line 6--6 ot Fig. 3;

Fig. 7 is a horizontal sectional view on the line 7-7 ot Fig. 5;

Fig. 8 is a rear view of the intermediate housing or rack, showing the automatic latching device from the rear; and

Fig. 9 is a rear View of the inner or upper rack.

Over-sized tires have rendered ordinary rack jacks practically useless at the present time for many makes ot cars, because they cannot raise a load to a height more than twice the height of the ack when contracted or lowered. This jack is designed to coinbine the simplicity of the ordinary vertical rack jacl with the possibility of extending the jack to a height approximately three times the height of the casing.

In the embodiment ot the invention shown herein, the jack is provided with and mounted in a casing 1() ot pressed inetal having a base 11, also of pressed metal riveted to it7 by flanges 12 at the bottom et the casing. This easing is provided with a vertical central passage, shown here as of a generally square shape in cross section, for receiving the parts that will be described. t is also provided with a substantially rectangular hollow proliection 13 for a purpose to be described, and on the other side extends out far enough to provide two walls; each having a perforation 1d 'for receiving the pivot pin 15 ot' an operating lever 16 which. is adapted to receive the handle. This casing is made preferably or' a single piece ot metal pressed into shape in dies.

In the central vertical passage in the casing is provided a reciprocable lift-ing member 17 which also is shown as square in cross section but having its front side open toward the operating lever 16. This is provided at the top with a flange 18 surrounding it on the three sides and at' one corner with a diagonal cross-pin 19 which extends into the interior far enough to form a stop for a purpose to be described.

Also the rear ot this member 17 is provided with an opening large enough to receive a movable latch and rack member 20.. This rack member is housed in the projectingpart 3 of the casii'ig. It is provided on the `front with rack teeth 21 and on the rear with a groove 22, in which is located a spring wire 23, preferably secured to this rack member by means ot a coil in the wire around a cross pin 24 su pported by the rack member. This spring extends beyond the rack member both above it and below it and is secured at its ends in two studs 25 liXedly mounted in the member 17. The tendency olY the spring` is to torce this rack member outwardly and backwardly into the hollow projection 13. The

top o't the rack member is rounded oil at its .upper end 26 on the back and the housing1 13 1s provided with a slantingg' surface 27 'for cooperating with it to force the rack member inwardly, when raised, where it comes into operative position as willvappear later. The casii'ig- 10 is provided with a slight enlargement above the projection 13 Yfor receiving` `the upper stud 25 as the rack is raised.

The inner telescoping rack member' consists of a piece of pressed metal. 30 having` a work- 'est 31 at the top, rack teeth 32 pressed into it and its operative 'face inside this member being;l also or rectangular shape also with the lront side omitted; that is, havin three walls only. The only other feature ot this is a pin 33 adapted to cooperate with the pin 19 previously described.

l/Vith this mechanism is used any desired lcind of a pawl arrangement cooperating' with the lever 16. I have shown here a pair ot' pawls 35 and 36 with a spring' 237, and ay setting lever 38 so that this lever can be set in either ot the two positions shown to cause the pawl accion to raise the racks or lower them.

In the operation oit the device, assun'iinp,I 'the parts to he in the position with both racks, that is, the members 30 and 17 at the bottom, so `that the worl -rcst 31 rests ust above the top ol the easing; 10. the lever 3S is set as shown in Fig'. 3 and the lever 16 is operated. The two pawls 35 and 3" cooperate to raise UU the rack 30 in the manner well-linown in this industry so that it need not bedescribed in detail.

Then the rack 30 is raised to a point where the pin 33 engages the pin 19, its turther movement upwardly one step will start up the lifting; member 17. The result of this is to draw the rack member 2O upwardly with it ol" course, so that the rounded upper end 26 will engage the inwardly slantinn surface 27 and force the parts into the position shown Ain 'Fi 4. It will heseen that this forces the upper end ot' the rack 21 into the same vertical planek as tlie rack teeth 32. Therefore the pawls will .inimediately commence toact upon this lower littinp; member 17 without any intermission or any change in the operation of the lever 16. At 4this time the rack 30 rests on the top ot the rack member 20, and, theretore, the former cannot descend or get released in any way. Thus the load is supported as rigidly as before. As the operation progresses the rack member 2O comes entirely inside the casing and eventually reaches a vertical position as shown in Fig. 5 where it will. serve as part ot the raclr. It will. be seen that, while the spring 23 is trying to torce this member outwardly away from the pawls, this is prevented by positive means, namely, the inside rear wallot the casing;` which engages the rear edges ot the rack member 20. This member is a little thicker at the center than at the ends which makes the bearing; point come halt way between the ends and allows a little play which may be needed at times. The rack member 20, however,is still housed within the opening in the member 17 at all times, so .that it cannot get out and can support the weight thatmay come upon it. rlhis weight is transmi tted through this member, so it is made strong.

@n the lowering ot the jack-the lever 38 is set in the opposite position as shown in Fig. 1, and then the operation ot the lever inthe usual way lowers the member 17 through the operation of the pawls on tlierrack member 2O until this member comes down to it lower` most position. At that time the raclr member is tree to swine` out into the opening in the hack ot the hollow member 17.' The spring 23 tends to pull it out immediately against the resistance due to the 'tact that the rack 30 is resting' upon 'its top. This is, ol course, assisted by the slantine; surface 27. Now this rack member no longer supports the raelr 30, but the teeth oi the latter are acted upon by Vthe pawls in the same way usual, so that it cau be lowered clear down to the bottom with no ditliculty whatever, always under the control oli the pawls.

This con. titutes a simple means 'for providi ne' a pressed steel 'jaclotthc vertical telescoping` rack type which will be capable ot being expanded to a little less thanthree times its minimum height; the pawl mechanism does not haie to be clianged, as any pawl mechanism that will operate satisfactorily on a single rack jack canbe used :tor this onewithout cham the parts are con Aiaratively simple and et euch a nature that they w'll operate automatically and certainly and inthe same way as is usual in rack aclrs of this greneral type, so no new method of operation has.

to be learned, and the addition tothe cost'of the ordinary single rack jackY is comparatively slight. Another important advantage is that it takes up practically no more room lll) with the exception of the projection 13 than an ordinary single rack ack.

Although I have illustrated and described only a single form of the invention I am aware of the fact that changes can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims.

Therefore I do not wish to be limited to the exact form shown, but what I do claim is l. In a lifting jack, the combination with a asing having a vertical passage, a lifting member located in said passage and movable up and down therein, and an inner rack movable up and down, of a pawl motion for operating the rack, and a movable raclr member movably mounted on the lifting member and movable to a position below the said inner rack and in line therewith so as to be operated on by the pawl mechanism.

2. In a lifting jack, the combination with a base and a casing lixedly mounted thereon, said casing having a vertical passage from the bottom to the top, of a lifting member located in said passage and movable up and down therein, an inner rack member located in the lifting member and movable up and down therein, a pawl motion for operating the rack, a movable rack mounted on the lifting member, and means whereby when the said lifting member is raised to a certain point the rack will be forced forward in the jack to a position below the said rack member and in line therewith so as to be operated on by the pawl mechanism.

3. In a lift-ing jack, the combination with a casing having a vertical passage therein, of a lower lifting member, a telescoping rack, pawl mechanism for raising and lowering said rack, a rack member movably carried by the lifting member, and means for forcing the rack member .inwardly into a position below the rack when the rack is raised just above it, so that the pawl mechanism will engage said rack member and raise the lifting member and the racl.

el. In a lifting ack, the combination with a casing having a vertical passage therein, of an outer lifting member hollow .in shape and open at one side, a rack mounted in the lifting member and adapted to be guided up and down therein, pawl mechanism for raising and lowering said raclr, a rack member carried by the lifting member, and means for yieldingly forcing the rack member back in the lifting member so as to rest behind the rack, said casing having means for forcing the rack member inwardly into a position below the rack when the raclr` is raised just above it, so that the pawl mechanism will engage said rack member and raise the lifting member and the rack.

5. In a lifting jack, the combination of a base, two telescoping lifting members slidable therein, the upper member having rack teeth, pawl mechanism for engaging in said teeth and raising or lowering the upper member, means whereby when the upper member is raised to a certain point it will pick up the lower member and carry it with it, and means carried by the lower member and adapted to move at that time into alignment with the rack teeth on the upper member and to support said inner member.

6. In a lift-ing ack, the combination of a base, two telescoping lifting members slidable therein, the outer of said members being U-shaped and the inner member being located within the outer member, the inner member having rack teeth on the front of its rear surface, pawl mechanism projecting into the inner member for engaging in said teeth and raising or lowering the inner member, means whereby when the inner member is raised to a certain point it will pick up the outer member and carry it with it, and means carried by the outer member and adapted to move at that time into vertical alignment with the rack teeth on the inner member and to support said inner member.

7. In a lifting jack, the combination with a casing and two telescoping lifting members slidable vertically therein, the inner member' having rack teeth thereon, means for engaging the rack teeth and raising and lowering the same, said outer member enclosing the inner member and having an opening through the back, a rack member located. in. said opening, yielding means for normally holding the rack member back in alignment with the rear `wall of the outer men'iber, and means for forcing the rack member, when the outer member is lifted from its original lowermost position, into alignment with the racl teeth on the inner member.

S. In a lifting ack, the combination with a casing and two telescoping lifting members slidable therein, the inner member having 'ack teeth thereon, means for engaging the rack teeth and raising and lowering the same, said outer member having an opening, a rack member located in said opening. means for normally holding the rack member back in the outer member, and means for forcing the rack member, when the outer member is lifted from its original lowermost position, into alignment with the rack teeth on the inner member.

In testimony whereof I have hereunto affixed my signature.

JOHN A. ADELL. 

